Yes, and they probably use phenol or something similarly toxic. They also use stabilzers in the emulsion that prevent fog and speed changes. The Osterman emulsion uses none of these. It is intended for immediate use.

For more information, look at the full formula posted by Jim Browning here and on his web site. There you see the list of stabilzers including Sodium Azide which is one of them and as a solid is explosive!

There is an additional aspect to this that you might consider. I think that it is counterproductive to make a big batch that lasts months. It is my strongly held opinion that you should be making small batches that won't need preservatives and that you should be making them often. Big batches might be OK if you had years and years of experience making emulsions so that the technical details and tactile memory would be there for you even after months had passed.

But, for most of us, practice makes perfect. It really is trivial to make a batch of emulsion, and the more times you do it, the easier and faster it gets. And, the quality improves. I don't think you'll ever become proficient making emulsions if you only give it a go twice a year.